Question

When an iron nail is dropped into a beaker containing a solution of copper sulphate, after a while, both the solution and the iron nail change colour. The nail gets a brownish coating and the solution turns green. The nail has a coating of Copper on its surface and the solution is detected to have the presence of an iron containing compound. Which kind of change does this experiment signify and why?
(a) Physical change, because the nail only changes color on the surface not the whole.
(b)Chemical change, due to deposit of a new substance on the nail.
(c)Physical change, due to deposit of a different substance on the nail’s surface.
(d)Chemical change, because both, solution and solvent have a change

Answer 1

Option (b) is the correct answer - Chemical change, due to the deposition of a new substance on the nail.

Explanation:

• This reaction infers that iron is more reactive than copper as it displaces copper from its solution and iron passes into solution as $Fe^{2+}$ ions and ferrous sulfate solution is formed.

• It is known as a double displacement reaction.

Double displacement reactions may be defined as the chemical reactions in which one component each of both the reacting molecules is exchanged to form the products

$Fe(s)\;+\;CuSO_{4\;}(aq)\rightarrow Cu(s)\;+\;FeSO_4(aq)$

• Here, the ferrous in iron nail and the copper from copper sulphate solution get exchanged with each other and forms Copper and Ferrous sulphate solution.

• Therefore, a chemical change took place due to the deposition of a new substance on the nail.

Answer 2

Answer:

opition b is correct

Explanation:

hope to is helpful